Generally, glass flakes are widely used in applications such as reinforcing materials for thermosetting resins and thermoplastic resins and fillers for corrosion-resistant linings.
For example, JP 62(1987)-109855 A describes a technique for enhancing the strength and dimensional stability of a thermoplastic resin by mixing glass flakes with the thermoplastic resin. JP 63(1988)-225554 A, JP 03(1991)-086753 A, JP 05(1993)-287175 A, JP 2002-212421 A, and JP 2003-082260 A each describe that flaky glass granules formed using a binder or a surface treatment agent are mixed with a thermoplastic resin.
Since glass flakes are thin scaly particles and have high scattering properties, they have the drawback of poor workability before being mixed with thermoplastic resins. Extruders are usually used when mixing glass flakes with thermoplastic resins. Since glass flakes are bulky and have poor flowability, they have the drawbacks such as clogging of extruder feeders and poor biting property to thermoplastic resins in extruders. In order to overcome these drawbacks, there has been developed a technique in which glass flakes are formed into granules using a binder or a surface treatment agent and then the granules are mixed with a thermoplastic resin.